Two decades ago, the Hollywood producer Harvey Weinstein invited Ashley Judd to the Peninsula Beverly Hills hotel for what the young actress expected to be a business breakfast meeting. Instead, he had her sent up to his room, where he appeared in a bathrobe and asked if he could give her a massage or she could watch him shower, she recalled in an interview.

“How do I get out of the room as fast as possible without alienating Harvey Weinstein?” Ms. Judd said she remembers thinking.

In 2014, Mr. Weinstein invited Emily Nestor, who had worked just one day as a temporary employee, to the same hotel and made another offer: If she accepted his sexual advances, he would boost her career, according to accounts she provided to colleagues who sent them to Weinstein Company executives. The following year, once again at the Peninsula, a female assistant said Mr. Weinstein badgered her into giving him a massage while he was naked, leaving her “crying and very distraught,” wrote a colleague, Lauren O’Connor, in a searing memo asserting sexual harassment and other misconduct by their boss.

“There is a toxic environment for women at this company,” Ms. O’Connor said in the letter, addressed to several executives at the company run by Mr. Weinstein.

An investigation by The New York Times found previously undisclosed allegations against Mr. Weinstein stretching over nearly three decades, documented through interviews with current and former employees and film industry workers, as well as legal records, emails and internal documents from the businesses he has run, Miramax and the Weinstein Company.

During that time, after being confronted with allegations including sexual harassment and unwanted physical contact, Mr. Weinstein has reached at least eight settlements with women, according to two company officials speaking on the condition of anonymity. Among the recipients, The Times found, were a young assistant in New York in 1990, an actress in 1997, an assistant in London in 1998, an Italian model in 2015 and Ms. O’Connor shortly after, according to records and those familiar with the agreements.

In a statement to The Times on Thursday afternoon, Mr. Weinstein said: “I appreciate the way I’ve behaved with colleagues in the past has caused a lot of pain, and I sincerely apologize for it. Though I’m trying to do better, I know I have a long way to go.”

He added that he was working with therapists and planning to take a leave of absence to “deal with this issue head on.”

Lisa Bloom, a lawyer advising Mr. Weinstein, said in a statement that “he denies many of the accusations as patently false.” In comments to The Times earlier this week, Mr. Weinstein said that many claims in Ms. O’Connor’s memo were “off base” and that they parted on good terms.